The document discusses ad hoc networks and wireless sensor networks. It defines an ad hoc network as a temporary network composed of mobile nodes without preexisting infrastructure that is self-organizing. Wireless sensor networks are introduced as a collection of sensor nodes densely deployed to monitor conditions and cooperatively pass data back to central nodes. The document outlines key characteristics of both networks including their temporary and adaptive nature, multi-hop routing, and challenges of mobility, power constraints, and dynamic topology changes.
Universal mobile telecommunication System (UMTS) is actually the third generation mobile, which uses WCDMA. The Dream was that 2G and 2.5G systems are incompatible around the world.
-Worldwide devices need to have multiple technologies inside of them, i.e. tri-band phones, dual-mode phones
To develop a single standard that would be accepted around the world.
-One device should be able to work anywhere.
Increased data rate.
- Maximum 2048Kbps
UMTS is developed by 3GPP (3 Generation Partnership Project) a joint venture of several organization
3G UMTS is a third-generation (3G): broadband, packet-based transmission of text, digitized voice, video, multimedia at data rates up to 2 Mbps
Also referred to as wideband code division multiple access(WCDMA)
Allows many more applications to be introduce to a worldwide
Also provide new services like alternative billing methods or calling plans.
The higher bandwidth also enables video conferencing or IPTV.
Once UMTS is fully available, computer and phone users can be constantly attached to the Internet wherever they travel and, as they roam, will have the same set of capabilities.
Wireless cellular networks divide geographic areas into cells served by base stations to allow for frequency reuse. As users travel between cells, their calls are handed off seamlessly. Cellular systems improve capacity by allocating unique frequency groups to each cell and reusing the same frequencies in cells sufficiently distant from each other. Larger networks connect multiple base stations and mobile switching centers to facilitate roaming and complete calls between mobile and fixed users.
The document discusses CDMA2000, a 3G cellular technology that provides an evolutionary upgrade path from 2G CDMA. It spreads signals across 1.25MHz of spectrum to transmit uniquely encoded signals simultaneously. CDMA2000 supports high-speed packet data through standards like 1X EV-DO that enable up to 2.4Mbps speeds. While it offers advantages like efficient spectrum use and support for advanced services, disadvantages include potential channel pollution from multiple signals and limited international roaming without multimode devices.
This document provides notes on ad hoc networks from R N S Institute of Technology. It begins with an introduction comparing cellular and ad hoc wireless networks. Ad hoc networks are infrastructureless networks that use multi-hop radio relaying. The document then discusses applications of ad hoc networks such as military operations, emergency response, wireless mesh networks, and wireless sensor networks. It also covers key issues in ad hoc networks including medium access, routing, multicasting, and energy management. The first unit focuses on these introductory concepts and applications of ad hoc networks.
This document summarizes geographical routing in wireless sensor networks. It begins with an introduction to geographic routing protocols, which route packets based on the geographic position of nodes rather than their network addresses. It then discusses several specific geographic routing protocols, including Greedy Perimeter Stateless Routing (GPSR) and Geographical and Energy Aware Routing (GEAR). The document also covers topics like how nodes obtain location information, security issues in geographic routing like the Sybil attack, and concludes that geographic routing can enable scalable and energy-efficient routing in wireless sensor networks.
This document discusses wireless sensor networks. It outlines their applications such as environmental monitoring, health care, and military uses. It also examines factors that influence sensor network design like fault tolerance, scalability, production costs, and power consumption. The communication architecture of sensor networks is presented, including the application, transport, network, data link, and physical layers. Sensor networks have the potential to be widely used in many applications due to their flexibility and fault tolerance.
Universal mobile telecommunication System (UMTS) is actually the third generation mobile, which uses WCDMA. The Dream was that 2G and 2.5G systems are incompatible around the world.
-Worldwide devices need to have multiple technologies inside of them, i.e. tri-band phones, dual-mode phones
To develop a single standard that would be accepted around the world.
-One device should be able to work anywhere.
Increased data rate.
- Maximum 2048Kbps
UMTS is developed by 3GPP (3 Generation Partnership Project) a joint venture of several organization
3G UMTS is a third-generation (3G): broadband, packet-based transmission of text, digitized voice, video, multimedia at data rates up to 2 Mbps
Also referred to as wideband code division multiple access(WCDMA)
Allows many more applications to be introduce to a worldwide
Also provide new services like alternative billing methods or calling plans.
The higher bandwidth also enables video conferencing or IPTV.
Once UMTS is fully available, computer and phone users can be constantly attached to the Internet wherever they travel and, as they roam, will have the same set of capabilities.
Wireless cellular networks divide geographic areas into cells served by base stations to allow for frequency reuse. As users travel between cells, their calls are handed off seamlessly. Cellular systems improve capacity by allocating unique frequency groups to each cell and reusing the same frequencies in cells sufficiently distant from each other. Larger networks connect multiple base stations and mobile switching centers to facilitate roaming and complete calls between mobile and fixed users.
The document discusses CDMA2000, a 3G cellular technology that provides an evolutionary upgrade path from 2G CDMA. It spreads signals across 1.25MHz of spectrum to transmit uniquely encoded signals simultaneously. CDMA2000 supports high-speed packet data through standards like 1X EV-DO that enable up to 2.4Mbps speeds. While it offers advantages like efficient spectrum use and support for advanced services, disadvantages include potential channel pollution from multiple signals and limited international roaming without multimode devices.
This document provides notes on ad hoc networks from R N S Institute of Technology. It begins with an introduction comparing cellular and ad hoc wireless networks. Ad hoc networks are infrastructureless networks that use multi-hop radio relaying. The document then discusses applications of ad hoc networks such as military operations, emergency response, wireless mesh networks, and wireless sensor networks. It also covers key issues in ad hoc networks including medium access, routing, multicasting, and energy management. The first unit focuses on these introductory concepts and applications of ad hoc networks.
This document summarizes geographical routing in wireless sensor networks. It begins with an introduction to geographic routing protocols, which route packets based on the geographic position of nodes rather than their network addresses. It then discusses several specific geographic routing protocols, including Greedy Perimeter Stateless Routing (GPSR) and Geographical and Energy Aware Routing (GEAR). The document also covers topics like how nodes obtain location information, security issues in geographic routing like the Sybil attack, and concludes that geographic routing can enable scalable and energy-efficient routing in wireless sensor networks.
This document discusses wireless sensor networks. It outlines their applications such as environmental monitoring, health care, and military uses. It also examines factors that influence sensor network design like fault tolerance, scalability, production costs, and power consumption. The communication architecture of sensor networks is presented, including the application, transport, network, data link, and physical layers. Sensor networks have the potential to be widely used in many applications due to their flexibility and fault tolerance.
ZRP divides routing into intrazone and interzone routing. Intrazone routing uses a proactive approach to route packets within a node's routing zone. Interzone routing uses a reactive approach where the source node sends route requests to peripheral nodes when the destination is outside its zone. The optimal zone radius depends on factors like mobility and query rates, with smaller radii preferred for higher mobility. ZRP aims to reduce routing overhead through techniques like restricting floods and maintaining multiple routes.
The document discusses ad hoc networks. It defines an ad hoc network as a temporary network connection between devices without fixed infrastructure. Key characteristics of ad hoc networks include dynamic topology, nodes that can freely join and leave, multi-hop routing, and limited bandwidth. The document compares ad hoc networks to wired and managed wireless networks. It also discusses different types of ad hoc networks and routing protocols like DSR and AODV. Applications of ad hoc networks include military operations, conferences, and emergency response situations.
2.5 capacity calculations of fdma, tdma and cdmaJAIGANESH SEKAR
The document discusses the capacity calculations of cellular systems using FDMA, TDMA, and CDMA. For FDMA systems, capacity is limited by co-channel interference and calculated based on channel bandwidth, frequency reuse factor, and signal-to-interference ratio. TDMA systems improve capacity over analog systems through techniques like timeslot allocation and adaptive channel assignment. CDMA systems can reuse the entire spectrum in all cells, and capacity is interference-limited rather than bandwidth-limited. Capacity is increased in CDMA through sectorization, monitoring voice activity, and controlling transmit power.
The document discusses the cellular concept in wireless networks. Key points include:
- Cells have a hexagonal shape and neighboring cells reuse frequencies to avoid interference and increase capacity.
- Frequency reuse allows more simultaneous calls by allocating the same set of frequencies to different neighboring cells.
- Cell size is a tradeoff between interference and system capacity - smaller cells mean lower power needs but more cells and handoffs.
This document summarizes several reactive routing protocols for mobile ad hoc networks (MANETs). Reactive protocols create routes only when needed by a source. Dynamic Source Routing uses route requests and replies to find paths, while Temporally-Ordered Routing Algorithm builds and maintains a directed acyclic graph rooted at destinations. Some protocols aim to improve quality of service or support real-time data streams through techniques like bandwidth estimation and mobility prediction. Source Routing with Local Recovery reduces overhead by allowing intermediate nodes to perform local error recovery using route caches when possible.
The document describes the key components and architecture of the GSM system. It discusses the objectives of GSM including supporting international roaming and good speech quality. It then describes the hierarchy of the GSM system including the mobile station, radio subsystem with base stations and base station controllers, and the network and switching subsystem with mobile switching centers and databases. It also discusses the air interface including frequency allocation and channel structure.
This document discusses mobility management (MM) in GPRS and UMTS networks. It describes the different MM states in GPRS (IDLE, STANDBY, READY) and UMTS (PMM-DETACHED, PMM-IDLE, PMM-CONNECTED). The MM contexts maintained by the MS, SGSN, and HLR/AUC are also outlined. Periodic and normal location update procedures performed by the MS to update its location are explained.
The document describes two wireless sensor network routing protocols: LEACH and PEGASIS. LEACH uses local processing to reduce global communication and randomly rotates cluster heads to distribute energy load. PEGASIS forms chains between nodes so that each node only communicates with a close neighbor, extending network lifetime compared to LEACH by up to 3 times. Both protocols aim to improve energy efficiency through data aggregation and minimizing transmission distances in wireless sensor networks.
The document discusses ad-hoc networks and their key characteristics. It describes several challenges in ad-hoc networks including limited battery power, dynamic network topology, and scalability issues. It also summarizes several ad-hoc network routing protocols (e.g. DSDV, AODV, DSR), addressing both table-driven and on-demand approaches. Additionally, it outlines some ad-hoc MAC protocols like MACA and PAMAS that aim to manage shared wireless medium access.
Global System for Mobile (GSM) is a second generation cellular standard developed for voice services and data delivery using digital modulation. It has a network subsystem including components like the MSC, HLR, VLR, and AuC that handle call processing and subscriber information. The radio subsystem consists of BSCs controlling multiple BTSs to manage radio network access. GSM provides international roaming, high quality voice calls, and supports data services like SMS and fax in addition to voice.
Improving coverage and capacity in cellular systemsTarek Nader
Cellular networks use various techniques to expand coverage and increase capacity as needs change over time, including cell splitting, beam tilting, cell sectoring, microcells, and frequency borrowing. Cell splitting involves dividing larger cells into smaller cells served by lower-power base stations to enable more spatial frequency reuse and greater system capacity, though it increases handoffs and costs. Beam tilting reduces interference between cells by tilting antenna beams downward. Cell sectoring divides cells into wedge-shaped sectors each with their own channels to decrease interference while reducing trunking efficiency. Microcells add capacity in hotspot areas without changing reuse factors. Frequency borrowing assigns congested cells frequencies from adjacent cells dynamically.
The document discusses several outdoor propagation models used to predict radio signal strength over long distances. It focuses on the Longley-Rice and Okumura models. The Longley-Rice model predicts transmission loss using terrain profiles and diffraction losses from obstacles. It is available as a computer program that inputs frequency, path length, antenna heights and terrain parameters. The Okumura model uses curves to predict median signal attenuation relative to free space over distances from 1-100 km based on frequency, distance from base station, and terrain factors. It is widely used for cellular predictions in urban environments.
Mobile computing unit2,SDMA,FDMA,CDMA,TDMA Space Division Multi Access,Frequ...Pallepati Vasavi
This document discusses various terminology related to the MAC sublayer, including:
1. The station model consisting of independent stations that generate frames for transmission.
2. The single channel assumption where a single channel is available for all communication.
3. The collision assumption where if two frames are transmitted simultaneously they will overlap and be garbled.
It then covers concepts such as carrier sensing, hidden and exposed terminals, and near and far terminals that create challenges for wireless networks. Finally, it introduces various multiple access methods including SDMA, FDMA, TDMA, and CDMA.
The document discusses various propagation mechanisms that affect radio signals, including reflection, diffraction, scattering, and their effects on signal strength over distance. It also covers propagation models like free space path loss, two-ray ground reflection model, and log-distance path loss for estimating average received signal power at a given distance. Fresnel zones and knife-edge diffraction are explained as factors in signal propagation around obstructions. Log-normal shadowing is described as a statistical model to account for variations from the average path loss.
LAR utilizes location information to improve routing efficiency by reducing control overhead. It uses GPS to obtain geographical information. There are two zones in LAR - the ExpectedZone where the destination is expected to be, and the RequestZone which is the area where routing packets can propagate. PAR aims to minimize energy consumption per packet by calculating the sum of energy required at each hop. It also aims for maximum network connectivity and uniform distribution of power consumption across all nodes.
1: Direct sequence and frequency hopped spread spectrum, spreading sequence and their correlation functions, Acquisition and tracking of spread spectrum signals.
2: Error probability for DS-CDMA, on AWGN channels, DS-CDMA on frequency selective fading, channels, Performance analysis of cellular CDMA.
3: Capacity estimation, Power control, effect of imperfect power control on DS CDMA performance, Soft Handoffs.
4: Spreading /coding tradeoffs, multi-carrier CDMA, IS-95 CDMA system, third generation CDMA systems, multi-user detection.
This document provides an overview of 3rd generation WCDMA/UMTS wireless networks. It describes the evolution from 2G to 3G networks and the key aspects of WCDMA/UMTS architecture, including the air interface, radio access network, core network and radio resource management functions such as admission control, load control, packet scheduling, handover control and power control. The document also briefly discusses additional topics such as radio network planning issues, high speed data packet access, and a comparison of WCDMA and CDMA2000.
This document discusses localization techniques in wireless sensor networks (WSNs). It begins with an introduction to WSNs and their applications that require location information. While GPS could provide location data, it is not practical for WSNs due to cost and physical constraints. The document then categorizes localization methods as range-based, which use distance or angle measurements, and range-free, which do not directly measure distance. Specific techniques like time of arrival, received signal strength, and DV-Hop localization are described. The document concludes with classifications of localization methods and topics for future work.
3G cellular networks aimed to provide higher bandwidth and data rates, global roaming, and support for multimedia services. The ITU defined the IMT-2000 standard to enable these capabilities. Major 3G technologies included W-CDMA, CDMA2000, and UWC-136. Early 3G networks rolled out starting in 2001, with the Japanese and Koreans among the first to offer services meeting IMT-2000 specifications. Key technologies like higher bandwidths, packet switching, coherent modulation, smart antennas, and interference management helped 3G networks provide improved performance over 2G networks.
Lecture 23 27. quality of services in ad hoc wireless networksChandra Meena
The document discusses quality of service (QoS) in mobile ad hoc networks (MANETs). It covers several key topics:
1) The challenges of providing QoS in MANETs due to their dynamic and decentralized nature.
2) Different approaches to QoS classification and provisioning at various network layers. This includes MAC layer solutions like IEEE 802.11e and network layer solutions like QoS-aware routing protocols.
3) Specific QoS routing protocols discussed, including ticket-based, predictive location-based, and trigger-based distributed protocols.
Lecture 19 22. transport protocol for ad-hoc Chandra Meena
This document discusses transport layer protocols for mobile ad hoc networks (MANETs). It begins with an introduction to MANETs and the need for new network architectures and protocols to support new types of networks. It then provides an overview of TCP/IP and how TCP works, including congestion control mechanisms. The document discusses challenges for TCP over wireless networks, where packet losses are often due to errors rather than congestion. It covers different versions of TCP and their approaches to congestion control. The goal is to design transport layer protocols that can address the unreliable links and frequent topology changes in MANETs.
ZRP divides routing into intrazone and interzone routing. Intrazone routing uses a proactive approach to route packets within a node's routing zone. Interzone routing uses a reactive approach where the source node sends route requests to peripheral nodes when the destination is outside its zone. The optimal zone radius depends on factors like mobility and query rates, with smaller radii preferred for higher mobility. ZRP aims to reduce routing overhead through techniques like restricting floods and maintaining multiple routes.
The document discusses ad hoc networks. It defines an ad hoc network as a temporary network connection between devices without fixed infrastructure. Key characteristics of ad hoc networks include dynamic topology, nodes that can freely join and leave, multi-hop routing, and limited bandwidth. The document compares ad hoc networks to wired and managed wireless networks. It also discusses different types of ad hoc networks and routing protocols like DSR and AODV. Applications of ad hoc networks include military operations, conferences, and emergency response situations.
2.5 capacity calculations of fdma, tdma and cdmaJAIGANESH SEKAR
The document discusses the capacity calculations of cellular systems using FDMA, TDMA, and CDMA. For FDMA systems, capacity is limited by co-channel interference and calculated based on channel bandwidth, frequency reuse factor, and signal-to-interference ratio. TDMA systems improve capacity over analog systems through techniques like timeslot allocation and adaptive channel assignment. CDMA systems can reuse the entire spectrum in all cells, and capacity is interference-limited rather than bandwidth-limited. Capacity is increased in CDMA through sectorization, monitoring voice activity, and controlling transmit power.
The document discusses the cellular concept in wireless networks. Key points include:
- Cells have a hexagonal shape and neighboring cells reuse frequencies to avoid interference and increase capacity.
- Frequency reuse allows more simultaneous calls by allocating the same set of frequencies to different neighboring cells.
- Cell size is a tradeoff between interference and system capacity - smaller cells mean lower power needs but more cells and handoffs.
This document summarizes several reactive routing protocols for mobile ad hoc networks (MANETs). Reactive protocols create routes only when needed by a source. Dynamic Source Routing uses route requests and replies to find paths, while Temporally-Ordered Routing Algorithm builds and maintains a directed acyclic graph rooted at destinations. Some protocols aim to improve quality of service or support real-time data streams through techniques like bandwidth estimation and mobility prediction. Source Routing with Local Recovery reduces overhead by allowing intermediate nodes to perform local error recovery using route caches when possible.
The document describes the key components and architecture of the GSM system. It discusses the objectives of GSM including supporting international roaming and good speech quality. It then describes the hierarchy of the GSM system including the mobile station, radio subsystem with base stations and base station controllers, and the network and switching subsystem with mobile switching centers and databases. It also discusses the air interface including frequency allocation and channel structure.
This document discusses mobility management (MM) in GPRS and UMTS networks. It describes the different MM states in GPRS (IDLE, STANDBY, READY) and UMTS (PMM-DETACHED, PMM-IDLE, PMM-CONNECTED). The MM contexts maintained by the MS, SGSN, and HLR/AUC are also outlined. Periodic and normal location update procedures performed by the MS to update its location are explained.
The document describes two wireless sensor network routing protocols: LEACH and PEGASIS. LEACH uses local processing to reduce global communication and randomly rotates cluster heads to distribute energy load. PEGASIS forms chains between nodes so that each node only communicates with a close neighbor, extending network lifetime compared to LEACH by up to 3 times. Both protocols aim to improve energy efficiency through data aggregation and minimizing transmission distances in wireless sensor networks.
The document discusses ad-hoc networks and their key characteristics. It describes several challenges in ad-hoc networks including limited battery power, dynamic network topology, and scalability issues. It also summarizes several ad-hoc network routing protocols (e.g. DSDV, AODV, DSR), addressing both table-driven and on-demand approaches. Additionally, it outlines some ad-hoc MAC protocols like MACA and PAMAS that aim to manage shared wireless medium access.
Global System for Mobile (GSM) is a second generation cellular standard developed for voice services and data delivery using digital modulation. It has a network subsystem including components like the MSC, HLR, VLR, and AuC that handle call processing and subscriber information. The radio subsystem consists of BSCs controlling multiple BTSs to manage radio network access. GSM provides international roaming, high quality voice calls, and supports data services like SMS and fax in addition to voice.
Improving coverage and capacity in cellular systemsTarek Nader
Cellular networks use various techniques to expand coverage and increase capacity as needs change over time, including cell splitting, beam tilting, cell sectoring, microcells, and frequency borrowing. Cell splitting involves dividing larger cells into smaller cells served by lower-power base stations to enable more spatial frequency reuse and greater system capacity, though it increases handoffs and costs. Beam tilting reduces interference between cells by tilting antenna beams downward. Cell sectoring divides cells into wedge-shaped sectors each with their own channels to decrease interference while reducing trunking efficiency. Microcells add capacity in hotspot areas without changing reuse factors. Frequency borrowing assigns congested cells frequencies from adjacent cells dynamically.
The document discusses several outdoor propagation models used to predict radio signal strength over long distances. It focuses on the Longley-Rice and Okumura models. The Longley-Rice model predicts transmission loss using terrain profiles and diffraction losses from obstacles. It is available as a computer program that inputs frequency, path length, antenna heights and terrain parameters. The Okumura model uses curves to predict median signal attenuation relative to free space over distances from 1-100 km based on frequency, distance from base station, and terrain factors. It is widely used for cellular predictions in urban environments.
Mobile computing unit2,SDMA,FDMA,CDMA,TDMA Space Division Multi Access,Frequ...Pallepati Vasavi
This document discusses various terminology related to the MAC sublayer, including:
1. The station model consisting of independent stations that generate frames for transmission.
2. The single channel assumption where a single channel is available for all communication.
3. The collision assumption where if two frames are transmitted simultaneously they will overlap and be garbled.
It then covers concepts such as carrier sensing, hidden and exposed terminals, and near and far terminals that create challenges for wireless networks. Finally, it introduces various multiple access methods including SDMA, FDMA, TDMA, and CDMA.
The document discusses various propagation mechanisms that affect radio signals, including reflection, diffraction, scattering, and their effects on signal strength over distance. It also covers propagation models like free space path loss, two-ray ground reflection model, and log-distance path loss for estimating average received signal power at a given distance. Fresnel zones and knife-edge diffraction are explained as factors in signal propagation around obstructions. Log-normal shadowing is described as a statistical model to account for variations from the average path loss.
LAR utilizes location information to improve routing efficiency by reducing control overhead. It uses GPS to obtain geographical information. There are two zones in LAR - the ExpectedZone where the destination is expected to be, and the RequestZone which is the area where routing packets can propagate. PAR aims to minimize energy consumption per packet by calculating the sum of energy required at each hop. It also aims for maximum network connectivity and uniform distribution of power consumption across all nodes.
1: Direct sequence and frequency hopped spread spectrum, spreading sequence and their correlation functions, Acquisition and tracking of spread spectrum signals.
2: Error probability for DS-CDMA, on AWGN channels, DS-CDMA on frequency selective fading, channels, Performance analysis of cellular CDMA.
3: Capacity estimation, Power control, effect of imperfect power control on DS CDMA performance, Soft Handoffs.
4: Spreading /coding tradeoffs, multi-carrier CDMA, IS-95 CDMA system, third generation CDMA systems, multi-user detection.
This document provides an overview of 3rd generation WCDMA/UMTS wireless networks. It describes the evolution from 2G to 3G networks and the key aspects of WCDMA/UMTS architecture, including the air interface, radio access network, core network and radio resource management functions such as admission control, load control, packet scheduling, handover control and power control. The document also briefly discusses additional topics such as radio network planning issues, high speed data packet access, and a comparison of WCDMA and CDMA2000.
This document discusses localization techniques in wireless sensor networks (WSNs). It begins with an introduction to WSNs and their applications that require location information. While GPS could provide location data, it is not practical for WSNs due to cost and physical constraints. The document then categorizes localization methods as range-based, which use distance or angle measurements, and range-free, which do not directly measure distance. Specific techniques like time of arrival, received signal strength, and DV-Hop localization are described. The document concludes with classifications of localization methods and topics for future work.
3G cellular networks aimed to provide higher bandwidth and data rates, global roaming, and support for multimedia services. The ITU defined the IMT-2000 standard to enable these capabilities. Major 3G technologies included W-CDMA, CDMA2000, and UWC-136. Early 3G networks rolled out starting in 2001, with the Japanese and Koreans among the first to offer services meeting IMT-2000 specifications. Key technologies like higher bandwidths, packet switching, coherent modulation, smart antennas, and interference management helped 3G networks provide improved performance over 2G networks.
Lecture 23 27. quality of services in ad hoc wireless networksChandra Meena
The document discusses quality of service (QoS) in mobile ad hoc networks (MANETs). It covers several key topics:
1) The challenges of providing QoS in MANETs due to their dynamic and decentralized nature.
2) Different approaches to QoS classification and provisioning at various network layers. This includes MAC layer solutions like IEEE 802.11e and network layer solutions like QoS-aware routing protocols.
3) Specific QoS routing protocols discussed, including ticket-based, predictive location-based, and trigger-based distributed protocols.
Lecture 19 22. transport protocol for ad-hoc Chandra Meena
This document discusses transport layer protocols for mobile ad hoc networks (MANETs). It begins with an introduction to MANETs and the need for new network architectures and protocols to support new types of networks. It then provides an overview of TCP/IP and how TCP works, including congestion control mechanisms. The document discusses challenges for TCP over wireless networks, where packet losses are often due to errors rather than congestion. It covers different versions of TCP and their approaches to congestion control. The goal is to design transport layer protocols that can address the unreliable links and frequent topology changes in MANETs.
The document discusses security issues in mobile ad hoc networks (MANETs). It begins by introducing MANETs and noting their vulnerability to attacks due to lack of centralized authority. It then covers security goals, types of attacks (passive vs. active; internal vs. external), examples of passive attacks like eavesdropping and active attacks like jamming and wormholes. The document also discusses security schemes like intrusion detection and secure routing techniques. It concludes by identifying research issues around improving MANET security.
Mobile ad-hoc networks have frequent host and topology changes with no cellular infrastructure and require multi-hop wireless links for data transmission between nodes. Routing protocols must discover routes between nodes that may not be directly connected. Table-driven protocols like Destination Sequenced Distance Vector (DSDV) and Wireless Routing Protocol (WRP) maintain up-to-date routing tables through periodic broadcasts but generate significant control overhead. DSDV uses sequence numbers to distinguish stale routes and avoid loops while WRP maintains four tables for routing information.
Lecture 7 8 ad hoc wireless media access protocolsChandra Meena
1) The document discusses issues with media access control (MAC) protocols in ad hoc wireless networks, including problems like hidden terminals and exposed nodes.
2) It classifies MAC protocols as synchronous, asynchronous, receiver-initiated, or sender-initiated. The RTS-CTS handshake is presented as a solution to the hidden terminal problem.
3) However, the RTS-CTS approach has shortcomings like collisions when RTS and CTS messages are sent by different nodes or when multiple CTS messages are granted. Solutions to the exposed node problem are also discussed.
Lecture 2 evolution of mobile cellular Chandra Meena
This document provides an overview of mobile and ad hoc networks. It discusses the evolution of cellular networks from early radio communication systems through modern generations like 5G. Key topics covered include the fundamentals of wireless technologies, radio propagation mechanisms, characteristics of the wireless channel, and cellular network components and terminology. Generations of cellular standards are defined, including 1G analog networks like AMPS, 2G digital networks like GSM that enabled data services, and subsequent generations with improved capabilities.
The document discusses on-demand driven reactive routing protocols. It provides an overview of table-driven vs on-demand routing protocols and describes two popular on-demand protocols - Dynamic Source Routing (DSR) and Ad Hoc On-Demand Distance Vector Routing (AODV) in detail. DSR uses source routing by adding the complete route to packet headers. AODV maintains routing tables at nodes and relies on dynamically establishing next hop information for routes.
1. Reinforcement learning involves an agent learning through trial-and-error interactions with an environment. The agent learns a policy for how to act by maximizing rewards.
2. The document outlines key elements of reinforcement learning including states, actions, rewards, value functions, and explores different methods for solving reinforcement learning problems including dynamic programming, Monte Carlo methods, and temporal difference learning.
3. Temporal difference learning combines the advantages of Monte Carlo methods and dynamic programming by allowing for incremental learning through bootstrapping predictions like dynamic programming while also learning directly from experience like Monte Carlo methods.
This document discusses the origins and development of ad hoc networks. It describes how packet radio networks (PRNETs) in the 1970s, developed by DARPA, were the first generation of ad hoc networks. PRNETs used multi-hop routing between mobile radio terminals and packet radios to communicate without fixed infrastructure. The document outlines the key components and routing techniques of PRNETs, including point-to-point and broadcast routing. It also discusses how subsequent generations in the 1980s-1990s focused on improving performance, scalability, and developing commercial applications like Bluetooth.
An ad hoc network is a type of wireless network that does not require a central router or base station. Nodes communicate directly with each other or through intermediate nodes in a multi-hop fashion without any fixed infrastructure. Routing and resource management are distributed. Common types include wireless mesh networks, wireless sensor networks, and hybrid wireless networks. Ad hoc networks face challenges related to medium access, routing, security, and resource constraints due to the lack of centralized control.
Lecture 1 mobile and adhoc network- introductionChandra Meena
This document provides an overview of a course on mobile and ad hoc networks. It lists two textbooks that will be used and states that the goal is to cover fundamental design issues and solutions for network architecture and protocols. It also lists some related websites and outlines the objectives of chapters that will introduce wireless communication technologies, network standards, and multiple access techniques for ad hoc networks.
Mobile ad-hoc networks (MANETs) were first developed in the 1970s by DARPA to allow packet radio connections between military terminals without infrastructure. MANETs allow devices to self-configure into a temporary network without centralized administration. They find applications in disaster relief, conferences, and more. Key challenges in MANETs include dynamic topology, limited bandwidth, energy constraints, and scalability issues as more devices join the network. Routing protocols must adapt to frequent changes, while providing quality of service, security, and other functions with distributed control.
This document provides an overview of mobile ad-hoc networks, including a brief history and introduction. It discusses the key differences between infrastructure-based networks and infrastructure-less networks. It also covers routing protocols, setting up a simple ad-hoc network, pros and cons of ad-hoc networks, wireless ad-hoc sensor networks, differences between cellular and ad-hoc networks, and future research directions.
An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...IOSR Journals
This document provides an overview of mobile ad hoc networks (MANETs), including their applications, challenges, and comparisons of routing protocols. It discusses how MANETs are self-configuring networks of mobile nodes that communicate wirelessly without centralized administration. The document outlines several applications of MANETs, technological challenges in areas like routing, security, and power consumption. It also classifies and compares several popular routing protocols for MANETs like DSDV, AODV, DSR, evaluating them based on parameters like route selection method, topology structure, and ability to avoid loops.
This document provides an overview of advanced networking concepts. It begins with learning objectives around data communication, network devices, protocols, topologies and network types. It then defines key networking components like switches, routers, and firewalls. It discusses different network topologies, media like Ethernet and wireless, and various network types including LAN, WAN, SAN and more. The document is intended to help readers understand fundamental networking concepts.
This document provides an overview of computer networking concepts. It discusses the components of a computer network including nodes, communication protocols, networking devices, network media, and common network types. It describes Local Area Networks (LANs), Wide Area Networks (WANs), and other network architectures. The document also outlines networking fundamentals such as the TCP/IP protocol suite, Ethernet, wireless networks, and network threats.
The document discusses computer networks and networking concepts. It begins by outlining the course content, which includes network types, media, threats, and cloud computing. It then defines what a computer network is and describes common network components like nodes, interconnections, and communication protocols. The document outlines different network types including LANs, WANs, MANs, SANs, and VPNs. It also discusses network devices, media, protocols, and advantages of networks.
This document provides an overview of computer networking concepts. It discusses the basic components of networks including nodes, communication protocols, network media, common network types, networking devices, network topologies and wireless networks. Specific topics covered include the Internet protocol suite, Ethernet, wireless LANs, fiber optic and copper cabling, bridges, switches, routers, firewalls, the client-server model and peer-to-peer networking. Network advantages like simultaneous access and easier data backup are also summarized.
This document provides an overview of computer networking concepts. It discusses the basic components of networks including nodes, communication protocols, network media, common network types, networking devices, network topologies and wireless networks. Specific topics covered include LANs, WANs, the TCP/IP protocol suite, Ethernet, fiber optic and twisted pair cabling, switches, routers, firewalls, the internet, cloud computing and wireless technologies like Bluetooth and Wi-Fi. The document is intended as an introductory course on computer networking fundamentals.
This document provides an overview of computer networking concepts. It discusses the basic components of networks including nodes, communication protocols, network media, common network types, networking devices, network topologies and wireless networks. Specific topics covered include LANs, WANs, the TCP/IP protocol suite, Ethernet, fiber optic and copper cabling, switches, routers, firewalls, the internet, cloud computing and wireless technologies like Bluetooth and Wi-Fi. The document is intended as an introductory course on computer networking fundamentals.
This document provides an overview of computer networking concepts. It discusses the basic components of networks including nodes, communication protocols, network media, common network types, networking devices, network topologies and wireless networks. Specific topics covered include LANs, WANs, the TCP/IP protocol suite, Ethernet, fiber optic and copper cabling, switches, routers, firewalls, the internet, cloud computing and wireless technologies like Bluetooth and Wi-Fi. The document is intended as an introductory course on computer networking fundamentals.
This document provides an overview of computer networking concepts. It discusses the basic components of networks including nodes, communication protocols, network media, common network types, and network topologies. Specific networking devices like switches, routers, and firewalls are defined. Wireless networking standards like Bluetooth and Wi-Fi are also mentioned. The purpose of computer networks to share resources located on network nodes is highlighted.
The document discusses computer networks and networking concepts. It begins by outlining the course content, which includes network types, uses of networks, network media, threats, and cloud computing. It then defines what a computer network is and describes common network components like nodes, interconnections, and communication protocols. The document outlines different network types including LANs, WANs, MANs, and more. It also discusses network devices, media, protocols, and advantages of networks.
Computer Network and its applications, different kinds of technologies and di...ssuser036308
The document discusses computer networks and networking concepts. It begins by outlining the course content, which includes network types, uses of networks, network media, threats, and cloud computing. It then defines what a computer network is and describes common network components like nodes, interconnections, and communication protocols. The document outlines different network types including LANs, WANs, MANs, SANs, and VPNs. It also discusses common networking devices, network media options, and example communication protocols.
A computer network links several computers. Office networks allow people to w...sherinjoyson
One of the first computer networks to use packet switching, ARPANET, was developed in the mid-1960s and is the direct predecessor of the modern Internet.
The Computer Network - All the basic Knowledgessuseree2ffc
A computer network is a group of computers/devices(Nodes) that use a set of common communication protocols over digital interconnections for the purpose of sharing resources located on or provided by the network nodes.
Network- computer networking by vinod pptDhruvilSTATUS
The document discusses computer networks and networking concepts. It begins by outlining the course content, which includes network types, uses of networks, network media, threats, and cloud computing. It then defines what a computer network is and describes common network components like nodes, interconnections, and communication protocols. The document outlines different network types including LANs, WANs, MANs, and more. It also discusses network devices, media, protocols, and advantages of networks.
This document provides an overview of computer networking concepts. It discusses the basic components of networks including nodes, communication protocols, network media, common network types, networking devices, network topologies and wireless networks. Specific topics covered include the Internet protocol suite, Ethernet, wireless LANs, fiber optic and copper cabling, bridges, switches, routers, firewalls, the client-server model and peer-to-peer networking. Network topologies such as bus, star, ring and mesh are defined along with short-range wireless technologies like Bluetooth and Wi-Fi. The document serves as an introductory guide to fundamental computer networking principles and technologies.
This document discusses a simulation of advanced networking using the GloMoSim simulator. It begins with an introduction by Dr. A. Kathirvel, a professor and head of the department of information technology. The document then covers topics like ad hoc wireless networks, research issues in mobile ad hoc networks, ad hoc wireless internet, and concludes with an outline of the simulator session.
Transcript: Details of description part II: Describing images in practice - T...BookNet Canada
This presentation explores the practical application of image description techniques. Familiar guidelines will be demonstrated in practice, and descriptions will be developed “live”! If you have learned a lot about the theory of image description techniques but want to feel more confident putting them into practice, this is the presentation for you. There will be useful, actionable information for everyone, whether you are working with authors, colleagues, alone, or leveraging AI as a collaborator.
Link to presentation recording and slides: https://bnctechforum.ca/sessions/details-of-description-part-ii-describing-images-in-practice/
Presented by BookNet Canada on June 25, 2024, with support from the Department of Canadian Heritage.
Video traffic on the Internet is constantly growing; networked multimedia applications consume a predominant share of the available Internet bandwidth. A major technical breakthrough and enabler in multimedia systems research and of industrial networked multimedia services certainly was the HTTP Adaptive Streaming (HAS) technique. This resulted in the standardization of MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH) which, together with HTTP Live Streaming (HLS), is widely used for multimedia delivery in today’s networks. Existing challenges in multimedia systems research deal with the trade-off between (i) the ever-increasing content complexity, (ii) various requirements with respect to time (most importantly, latency), and (iii) quality of experience (QoE). Optimizing towards one aspect usually negatively impacts at least one of the other two aspects if not both. This situation sets the stage for our research work in the ATHENA Christian Doppler (CD) Laboratory (Adaptive Streaming over HTTP and Emerging Networked Multimedia Services; https://athena.itec.aau.at/), jointly funded by public sources and industry. In this talk, we will present selected novel approaches and research results of the first year of the ATHENA CD Lab’s operation. We will highlight HAS-related research on (i) multimedia content provisioning (machine learning for video encoding); (ii) multimedia content delivery (support of edge processing and virtualized network functions for video networking); (iii) multimedia content consumption and end-to-end aspects (player-triggered segment retransmissions to improve video playout quality); and (iv) novel QoE investigations (adaptive point cloud streaming). We will also put the work into the context of international multimedia systems research.
INDIAN AIR FORCE FIGHTER PLANES LIST.pdfjackson110191
These fighter aircraft have uses outside of traditional combat situations. They are essential in defending India's territorial integrity, averting dangers, and delivering aid to those in need during natural calamities. Additionally, the IAF improves its interoperability and fortifies international military alliances by working together and conducting joint exercises with other air forces.
Hire a private investigator to get cell phone recordsHackersList
Learn what private investigators can legally do to obtain cell phone records and track phones, plus ethical considerations and alternatives for addressing privacy concerns.
Interaction Latency: Square's User-Centric Mobile Performance MetricScyllaDB
Mobile performance metrics often take inspiration from the backend world and measure resource usage (CPU usage, memory usage, etc) and workload durations (how long a piece of code takes to run).
However, mobile apps are used by humans and the app performance directly impacts their experience, so we should primarily track user-centric mobile performance metrics. Following the lead of tech giants, the mobile industry at large is now adopting the tracking of app launch time and smoothness (jank during motion).
At Square, our customers spend most of their time in the app long after it's launched, and they don't scroll much, so app launch time and smoothness aren't critical metrics. What should we track instead?
This talk will introduce you to Interaction Latency, a user-centric mobile performance metric inspired from the Web Vital metric Interaction to Next Paint"" (web.dev/inp). We'll go over why apps need to track this, how to properly implement its tracking (it's tricky!), how to aggregate this metric and what thresholds you should target.
The Rise of Supernetwork Data Intensive ComputingLarry Smarr
Invited Remote Lecture to SC21
The International Conference for High Performance Computing, Networking, Storage, and Analysis
St. Louis, Missouri
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Scaling Connections in PostgreSQL Postgres Bangalore(PGBLR) Meetup-2 - MydbopsMydbops
This presentation, delivered at the Postgres Bangalore (PGBLR) Meetup-2 on June 29th, 2024, dives deep into connection pooling for PostgreSQL databases. Aakash M, a PostgreSQL Tech Lead at Mydbops, explores the challenges of managing numerous connections and explains how connection pooling optimizes performance and resource utilization.
Key Takeaways:
* Understand why connection pooling is essential for high-traffic applications
* Explore various connection poolers available for PostgreSQL, including pgbouncer
* Learn the configuration options and functionalities of pgbouncer
* Discover best practices for monitoring and troubleshooting connection pooling setups
* Gain insights into real-world use cases and considerations for production environments
This presentation is ideal for:
* Database administrators (DBAs)
* Developers working with PostgreSQL
* DevOps engineers
* Anyone interested in optimizing PostgreSQL performance
Contact info@mydbops.com for PostgreSQL Managed, Consulting and Remote DBA Services
Coordinate Systems in FME 101 - Webinar SlidesSafe Software
If you’ve ever had to analyze a map or GPS data, chances are you’ve encountered and even worked with coordinate systems. As historical data continually updates through GPS, understanding coordinate systems is increasingly crucial. However, not everyone knows why they exist or how to effectively use them for data-driven insights.
During this webinar, you’ll learn exactly what coordinate systems are and how you can use FME to maintain and transform your data’s coordinate systems in an easy-to-digest way, accurately representing the geographical space that it exists within. During this webinar, you will have the chance to:
- Enhance Your Understanding: Gain a clear overview of what coordinate systems are and their value
- Learn Practical Applications: Why we need datams and projections, plus units between coordinate systems
- Maximize with FME: Understand how FME handles coordinate systems, including a brief summary of the 3 main reprojectors
- Custom Coordinate Systems: Learn how to work with FME and coordinate systems beyond what is natively supported
- Look Ahead: Gain insights into where FME is headed with coordinate systems in the future
Don’t miss the opportunity to improve the value you receive from your coordinate system data, ultimately allowing you to streamline your data analysis and maximize your time. See you there!
GDG Cloud Southlake #34: Neatsun Ziv: Automating AppsecJames Anderson
The lecture titled "Automating AppSec" delves into the critical challenges associated with manual application security (AppSec) processes and outlines strategic approaches for incorporating automation to enhance efficiency, accuracy, and scalability. The lecture is structured to highlight the inherent difficulties in traditional AppSec practices, emphasizing the labor-intensive triage of issues, the complexity of identifying responsible owners for security flaws, and the challenges of implementing security checks within CI/CD pipelines. Furthermore, it provides actionable insights on automating these processes to not only mitigate these pains but also to enable a more proactive and scalable security posture within development cycles.
The Pains of Manual AppSec:
This section will explore the time-consuming and error-prone nature of manually triaging security issues, including the difficulty of prioritizing vulnerabilities based on their actual risk to the organization. It will also discuss the challenges in determining ownership for remediation tasks, a process often complicated by cross-functional teams and microservices architectures. Additionally, the inefficiencies of manual checks within CI/CD gates will be examined, highlighting how they can delay deployments and introduce security risks.
Automating CI/CD Gates:
Here, the focus shifts to the automation of security within the CI/CD pipelines. The lecture will cover methods to seamlessly integrate security tools that automatically scan for vulnerabilities as part of the build process, thereby ensuring that security is a core component of the development lifecycle. Strategies for configuring automated gates that can block or flag builds based on the severity of detected issues will be discussed, ensuring that only secure code progresses through the pipeline.
Triaging Issues with Automation:
This segment addresses how automation can be leveraged to intelligently triage and prioritize security issues. It will cover technologies and methodologies for automatically assessing the context and potential impact of vulnerabilities, facilitating quicker and more accurate decision-making. The use of automated alerting and reporting mechanisms to ensure the right stakeholders are informed in a timely manner will also be discussed.
Identifying Ownership Automatically:
Automating the process of identifying who owns the responsibility for fixing specific security issues is critical for efficient remediation. This part of the lecture will explore tools and practices for mapping vulnerabilities to code owners, leveraging version control and project management tools.
Three Tips to Scale the Shift Left Program:
Finally, the lecture will offer three practical tips for organizations looking to scale their Shift Left security programs. These will include recommendations on fostering a security culture within development teams, employing DevSecOps principles to integrate security throughout the development
UiPath Community Day Kraków: Devs4Devs ConferenceUiPathCommunity
We are honored to launch and host this event for our UiPath Polish Community, with the help of our partners - Proservartner!
We certainly hope we have managed to spike your interest in the subjects to be presented and the incredible networking opportunities at hand, too!
Check out our proposed agenda below 👇👇
08:30 ☕ Welcome coffee (30')
09:00 Opening note/ Intro to UiPath Community (10')
Cristina Vidu, Global Manager, Marketing Community @UiPath
Dawid Kot, Digital Transformation Lead @Proservartner
09:10 Cloud migration - Proservartner & DOVISTA case study (30')
Marcin Drozdowski, Automation CoE Manager @DOVISTA
Pawel Kamiński, RPA developer @DOVISTA
Mikolaj Zielinski, UiPath MVP, Senior Solutions Engineer @Proservartner
09:40 From bottlenecks to breakthroughs: Citizen Development in action (25')
Pawel Poplawski, Director, Improvement and Automation @McCormick & Company
Michał Cieślak, Senior Manager, Automation Programs @McCormick & Company
10:05 Next-level bots: API integration in UiPath Studio (30')
Mikolaj Zielinski, UiPath MVP, Senior Solutions Engineer @Proservartner
10:35 ☕ Coffee Break (15')
10:50 Document Understanding with my RPA Companion (45')
Ewa Gruszka, Enterprise Sales Specialist, AI & ML @UiPath
11:35 Power up your Robots: GenAI and GPT in REFramework (45')
Krzysztof Karaszewski, Global RPA Product Manager
12:20 🍕 Lunch Break (1hr)
13:20 From Concept to Quality: UiPath Test Suite for AI-powered Knowledge Bots (30')
Kamil Miśko, UiPath MVP, Senior RPA Developer @Zurich Insurance
13:50 Communications Mining - focus on AI capabilities (30')
Thomasz Wierzbicki, Business Analyst @Office Samurai
14:20 Polish MVP panel: Insights on MVP award achievements and career profiling
The DealBook is our annual overview of the Ukrainian tech investment industry. This edition comprehensively covers the full year 2023 and the first deals of 2024.
Performance Budgets for the Real World by Tammy EvertsScyllaDB
Performance budgets have been around for more than ten years. Over those years, we’ve learned a lot about what works, what doesn’t, and what we need to improve. In this session, Tammy revisits old assumptions about performance budgets and offers some new best practices. Topics include:
• Understanding performance budgets vs. performance goals
• Aligning budgets with user experience
• Pros and cons of Core Web Vitals
• How to stay on top of your budgets to fight regressions
AC Atlassian Coimbatore Session Slides( 22/06/2024)apoorva2579
This is the combined Sessions of ACE Atlassian Coimbatore event happened on 22nd June 2024
The session order is as follows:
1.AI and future of help desk by Rajesh Shanmugam
2. Harnessing the power of GenAI for your business by Siddharth
3. Fallacies of GenAI by Raju Kandaswamy
2. Introduction
Introduction - Ad Hoc Network definition
Characteristic/features and application
Heterogeneity in Mobile Devices
Wireless Sensor Networks
Traffic Profiles
Types ofAd Hoc Mobile Communications
Types of Mobile Host Movements
Challenges FacingAd Hoc Mobile Networks
Issues and Challenges Facing Ad Hoc Mobile network
Ad Hoc wireless Internet
2
3. A BSS without an AP is called an ad hoc network;
a BSS with an AP is called an infrastructure network.
3
4. Ad hoc networks
Temporary network composed of mobile nodes without preexisting
communication infrastructure, such as Access Point (AP) and Base Station
(BS).
Each node plays the role of router for multi-hop routing.
Self-organizing network without infrastructure networks
Started from DARPA PRNet in 1970
Cooperative nodes (wireless)
Each node decode-and-forward packets for other nodes
Multi-hop packet forwarding through wireless links
Proactive/reactive/hybrid routing protocols
Most works based on CSMA/CA to solve the interference problem
IEEE 802.11 MAC
4
5. What Is an Ad Hoc Network?
An ad hoc wireless network
collection of two or more devices equipped with
wireless communications and networking capability.
Such devices can communicate with another node that is
immediately within their radio range or one that is outside
their radio range.
For the latter scenario, an intermediate node is used to relay or
forward the packet from the source toward the destination.
Since an ad hoc wireless network does not rely on any fixed
network entities, the network itself is essentially infrastructure-
less.There is no need for any fixed radio base stations, no wires or
fixed routers.
5
6. (cont…)
An ad hoc wireless network is self-organizing and adaptive.
This means that a formed network can be de-formed on-the-
fly without the need for any system administration.
The term "ad hoc" tends to imply "can take different
forms" and "can be mobile, standalone, or
networked.“
Ad hoc nodes or devices should be able to detect the
presence of other such devices and to perform the necessary
handshaking to allow communications and the sharing of
information and services.
6
7. Wireless Ad-hoc Network
A wireless ad-hoc network is a decentralized type
of wireless network.
The network is ad hoc because it does not rely on a pre-
existing infrastructure, such as routers in wired networks
or access points in managed (infrastructure) wireless
networks.
Each node participates in routing by forwarding data for other
nodes, and so the determination of which nodes forward data
is made dynamically based on the network connectivity.
In addition to the classic routing, ad hoc networks can
use flooding for forwarding the data.
7
8. Mobile Ad Hoc Networks (MANET)
Mobile nodes
Access points
Backbone
Wireless Mobile Network
MANET
8
9. Mobile Ad-hoc Network
Self-configuring network of mobile routers (and associated
hosts) connected by wireless links
This union forms a random topology
Routers move randomly free
Topology changes rapidly and unpredictably
Standalone fashion or connected to the larger Internet
While MANETs are self contained, they can also be tied to an
IP-based global or local network – Hybrid MANETs
Suitable for emergency situations like natural or human-induced
disasters, military conflicts, emergency medical situations, etc.
9
12. MANET Application
Applications Descriptions/Services
Tactical Networks •Military communication, operations
•Coordination of military object moving at high speeds such as fleets
of airplanes or ships
•Automated battlefields
Sensor networks •Collection of embedded sensor devices used to collect real time data
to automate everyday functions. Data highly correlated in time and
space, e.g., remote sensors for weather, earth activities; sensors for
manufacturing equipments.
•Can have between 1000 -100,000 nodes, each node collecting sample
data, then forwarding data to centralized host for processing using low
homogeneous rates.
Emergency
services
•Search, rescue, crowd control, and commando operations as well as
disaster recovery
•for e.g. Early retrieval and transmission of patient data ( record,
status, diagnosis ) from /to the hospital
•Replacement of a fixed infrastructure in case of earthquakes,
hurricanes, fire etc.12
13. MANET Application
Applications Descriptions/Services
Commercial
environments
•E-commerce, e.g., electronic payments from anywhere (i.e., in taxi).
•Business:
dynamic access to customer files stored in a central location
on the fly provide consistent databases for all agents
Mobile office
•Vehicular services:
transmission of news ,road conditions ,weather, music
local ad hoc network with nearby vehicles for road/accident
guidance
Home and
enterprise
networking
•Home/office wireless networking(WLAN), e.g., shared whiteboard
application, use PDA to print anywhere, trade shows
•Personal area network (PAN)
Educational
applications
•Set up virtual classrooms or conference rooms
•Set up ad hoc communication during conferences, meetings, or
lectures13
14. MANET Application
Applications Descriptions/Services
Entertainment Multiuser games
Robotic pets
outdoor internet access
Location- aware
Services
Follow- on services, e.g., automatic call forwarding, transmission of the
actual workspace to the current location
Information services
push, e.g., advertise location-specific services, like gas stations
pull, e.g., location-dependent travel guide; services( printer, fax,
phone, server, gas stations) availability information; caches,
intermediate results, state information, etc.
14
15. Issues in Ad-Hoc
Ad hoc wireless devices can take different forms (for example,
palmtop, laptop, Internet mobile phone, etc.), the computation,
storage, and communications capabilities and
interoperability of such devices will vary tremendously.
Ad hoc devices should not only detect the presence of connectivity
with neighbouring devices/nodes, but also identify what type the
devices are and their corresponding attributes.
Due to the presence of mobility, routing information will have to
change to reflect changes in link connectivity.
The diversity of ad hoc mobile devices also implies that the battery
capacity of such devices will also vary. Since ad hoc networks rely on
forwarding data packets sent by other nodes, power consumption
becomes a critical issue.15
16. Heterogeneity in Mobile Devices
(a) Heterogeneous mobile device ad hoc networks, and (b) homogeneous ad hoc
network comprising powerful laptop computers.16
17. Heterogeneity in Mobile Devices
The presence of heterogeneity implies that some devices are
more powerful than others, and some can be servers while
others can only be clients.
It is evident that there are differences in size, computational
power, memory, disk, and battery capacity.
Mobile devices can exist in many forms.There are great
differences among these devices,
heterogeneity can affect communication performance and
the design of communication protocols.
17
21. INTRODUCTION TO WSN
A wireless sensor network is one form of an ad hoc wireless
network.
A sensor network is a collection of a large number of
sensor nodes that are deployed in a particular region.
Sensors are wirelessly connected and they, at appropriate times, relay
information back to some selected nodes.
These selected nodes then perform some computation based on the
collected data to derive an ultimate statistic to allow critical
decisions to be made.
There are a variety of sensors, including acoustic(sound related) ,
seismic (Subject to an earthquake or earth vibration), image, heat,
direction, smoke, and temperature sensors.
21
22. Basic features of sensor networks
A large number of low-cost, low-power, multifunctional, and small sensor
nodes
Sensor node consists of sensing, data processing, and communicating
components
A sensor network is composed of a large number of sensor nodes,
which are densely deployed either inside the phenomenon or very close
to it.
The position of sensor nodes need not be engineered or pre-determined.
sensor network protocols and algorithms must possess self-organizing
capabilities.
22
23. Basic features of sensor networks
Self-organizing capabilities
Short-range broadcast communication and multihop routing
Dense deployment and cooperative effort of sensor nodes
Frequently changing topology due to fading and node
failures
Limitations in energy, transmit power, memory, and computing
power
23
24. Wireless Sensor Networks
A sort of ad-hoc networks
A network of low cost,
densely deployed,
untethered sensor nodes
Application areas:
heath, military, and home
Placed in inaccessible terrains or disaster areas
It may be impossible to recharge batteries
Different Node Characteristics fromTraditional nodes
No of nodes in a sensor network can be several orders of magnitude higher than
the nodes in an Ad Hoc network (100s to 1000s nodes)
Densely deployed (20 nodes/m3)
Mobility of nodes is not mendatory
Prone to failures
Topology changes very frequently
Mainly use a broadcast communication, whereas most Ad Hoc networks are based
on point-to-point
Limited in power, computing capacities, and memory
May not have global ID because of the large amount of overhead and large number
of sensors
Ad Hoc Net
Wireless
Sensor
Network
24
25. Existing Wireless Net vs. Sensor Net
Cellular system Bluetooth, MANET Sensor Network
Single Hop Multi-hop Multi-hop
High QOS
Bandwidth efficiency
High QOS Power conservation
Limited bandwidth
Large number of node
Narrow radio range
Frequent topology change
Station to Base station Peer to peer
Peer to multi node
Peer to multi node
25
28. Sensor Networks Architecture
Sensor node
Made up of four basic components
Sensing unit, Processing unit,Transceiver unit, and Power unit
Additional application-dependent components
Location finding system, power generator, and mobilizer
Scattered in a sensor field
Collect data and route data back to the sink
Sink
Communicate with the task manager node (user) via Internet
or satellite
28
29. Components of Sensor Node
A sensor node is made up of four basic components
sensing unit
usually composed of two subunits: sensors and analog to digital converters
(ADCs).
processing unit,
Manages the procedures that make the sensor node collaborate with the other
nodes to carry out the assigned sensing tasks.
Transceiver unit
Connects the node to the network.
Power units (the most important unit)
29
30. Sensor network topology
Pre-deployment and deployment phase
Sensor nodes can be either thrown in mass or placed one by one in
the sensor field.
Post-deployment phase
Sensor network topologies are prone to frequent changes after
deployment.
Re-deployment of additional nodes phase
Addition of new nodes poses a need to re-organize the network.
30
32. Environment
Sensor nodes may be working
in busy intersections,
in the interior of a large machinery,
at the bottom of an ocean,
inside a twister,
in a battlefield beyond the enemy lines,
in a home or a large building
Transmission media
Industrial, scientific and medical (ISM) bands
offer license-free communication in most countries.
Infrared
License-free and robust to interference
requirement of a line of sight between sender and receiver
32
33. Micro-sensors
Uses
In military: surveillance and target tracing
health-care industry: allow continuous monitoring of life-
critical information.
food industry: biosensor technology applied to quality control
can help prevent rejected products from being shipped out,
Agriculture: help to determine the quality of soil and moisture
level; they can also detect other bio-related compounds.
Sensors are also widely used for environmental and weather
information gathering.They enable us to make preparations in
times of bad weather and natural disaster.
33
35. Wireless Mesh Networks
Mesh networking is the holy grail of wireless networking.
“Mesh” refers to many types of technology that enable
wireless systems to automatically find each other and self-
configure themselves to route information amongst
themselves.
35
36. 36
Wireless Mesh Networks
Mesh network implemented over
WLAN
“Mesh” refers to many types of
technology that enable wireless
systems to automatically find each
other and self-configure themselves to
route information amongst themselves.
Industrial standardsActivities
IEEE 802.11, IEEE 802.15, IEEE
801.16 have established sub-working
groups to focus on new standards for
WMNs
37. In a wireless mesh network, the network connection is spread out among
dozens or even hundreds of wireless mesh nodes that "talk" to each other
to share the network connection across a large area.
Mesh nodes are small radio transmitters that function in the same way as a
wireless router.
In a wireless mesh network, only one node needs to be physically
wired to a network connection like a DSL Internet modem.That
one wired node then shares its Internet connection wirelessly with all other
nodes in its vicinity.Those nodes then share the connection wirelessly with
the nodes closest to them.The more nodes, the further the connection
spreads, creating a wireless "cloud of connectivity" that can serve a small
office or a city of millions.
37
38. Wireless Mesh Networks
Possible deployment scenarios:
Residential zone : where broadband connectivity is required
Highway: where a communication facility for moving automobiles
is required
Business zones: where an alternative communication system to
cellular network is required
Important civilian regions: where a high degree of service
availability is required
University campus: where inexpensive campus wide network
coverage can be provided.
Operates at license-free ISM band -2.4 GHz and 5 GHz.
Speed - 2Mbps to 60 Mbps38
40. Benefits
Using fewer wires means it costs less to set up a network, particularly for large areas of coverage.
The more nodes you install, the bigger and faster your wireless network becomes.
They rely on the same WiFi standards (802.11a, b and g) already in place for most wireless
networks.
They are convenient where Ethernet wall connections are lacking -- for instance, in
outdoor concert venues, warehouses or transportation settings.
They are useful for Non-Line-of-Sight (NLoS) network configurations where wireless
signals are intermittently blocked. For example, in an amusement park a Ferris wheel occasionally
blocks the signal from a wireless access point.
Wireless mesh configurations allow local networks to run faster, because local packets don't
have to travel back to a central server.
Wireless mesh nodes are easy to install and uninstall, making the network extremely adaptable and
expandable as more or less coverage is needed.
40
41. Electric meters now being deployed on residences transfer their readings from
one to another and eventually to the central office for billing without the need
for human meter readers or the need to connect the meters with cables.
Mesh networks are "self configuring;" the network automatically incorporates a
new node into the existing structure without needing any adjustments by a
network administrator.
Mesh networks are "self healing," since the network automatically finds the
fastest and most reliable paths to send data, even if nodes are blocked or lose
their signal.
41
43. 43
Mesh vs. Ad-Hoc Networks
Multihop
Nodes are wireless, possibly
mobile
May rely on infrastructure
Most traffic is user-to-user
Ad-Hoc Networks Wireless Mesh Networks
Multihop
Nodes are wireless,
some mobile, some
fixed
It relies on
infrastructure
Most traffic is user-
to-gateway
44. 44
Mesh vs. Sensor Networks
Bandwidth is limited (tens of kbps)
In most applications, fixed nodes
Energy efficiency is an issue
Resource constrained
Most traffic is user-to-gateway
Wireless Sensor Networks Wireless Mesh Networks
Bandwidth is generous (>1Mbps)
Some nodes mobile, some fixed
Normally not energy limited
Resources are not an issue
Most traffic is user-to-gateway
47. 47
WMN Architecture
WMNs (Wireless Mesh Networks) consist of:
mesh routers and mesh clients
Mesh routers
Conventional wireless AP (Access Point) functions
Additional mesh routing functions to support multi-hop communications
Usually multiple wireless interfaces built on either the same or different
radio technologies
Mesh clients
Can also work as a router for clientWMN
Usually one wireless interface
Classification ofWMN architecture
Infrastructure/BackboneWMNs
ClientWMNs
HybridWMNs
50. 50
Hybrid WMNs
Wi-Fi, Wi-MAX,
Sensor Networks,
Cellular Networks, etc.
Internet
Wireless Mesh Clients
Wireless Mesh
Backbone
Conventional Clients
Mesh Router
Mesh Router
Mesh Router
with Gateway
Mesh Router
with Gateway
Mesh Router
with Gateway/Bridge
Mesh Router Mesh Router
Mesh Router
with Gateway/Bridge
51. Types of Ad Hoc Mobile
Communications
Mobile hosts in an ad hoc mobile network can communicate
with their immediate peers (peer-to-peer) that are a single
radio hop away.
If three or more nodes are within range of each other (but
not necessarily a single hop away from one another), then
remote-to-remote mobile node communications
exist.
Remote-to-remote communications are associated with
group migrations.
51
52. Types of traffic patterns in Adhoc
Ad hoc wireless communications can occur in several different
forms.
1) Peer-to-peer communication
Mobile host communicates in pair
For a pair of ad hoc wireless nodes, communications will occur
between them over a period of time until the session is
finished or one of the nodes has moved away.
2) Remote-to-remote communication
when two or more devices are communicating among
themselves and they are migrating in groups.
The traffic pattern is, therefore, one where communications
occur over a longer period of time.
52
53. Types of traffic patterns in Adhoc
3) Hybrid Communication
have a scenario where devices communicate in a non-
coherent fashion and their communication sessions are,
therefore, short, abrupt, and undeterministic.
MH: Mobile host
53
54. Types of Mobile Host Movements
Movements by Nodes in a Route
Movements by Subnet-Bridging Nodes
Concurrent Node Movements
54
55. Movements by Nodes in a Route
Source nodes
Downstream
link
Intermediate
nodes
Destination
nodes
Upstream
link
55
56. Cont…
An ad hoc route comprises the source (SRC), destination (DEST), and/or a
number of intermediate nodes (INs).
Movement by any of these nodes will affect the validity of the route.
An SRC node
has a downstream link, and
when moves out of its downstream neighbour's radio coverage range, the existing
route will immediately become invalid.
all downstream nodes may have to be informed so they can erase their invalid route
entries.
DEST node
moves out of the radio coverage of its upstream neighbour, the route becomes
invalid.
The upsteam nodes will have to be informed so they can erase their invalid route
entries.
IN node : any movement by an IN supporting an existing route may cause the
route to be invalid.
56
57. Movements cause many conventional distributed routing
protocols to respond in sympathy with the link changes.
Need to update all the remaining nodes within the network
so that consistent routing information can be maintained.
Updating process involves broadcasting over the
wireless medium, which results in wasteful bandwidth and
an increase in overall network control traffic. Hence, new
routing protocols are needed.
57
58. Movements by Subnet-Bridging Nodes
Subnet-bridging node movement
between two mobile subnets can
fragment the mobile subnet into
smaller subnets
Movements by certain nodes can
result in subnets merging (yielding
bigger subnets) while sometimes
subnet is partitioned by some subnet-
bridging mobile nodes
Updating all the nodes' routing tables
Choose to update only the affected
nodes' association tables.
58
59. Concurrent movements by nodes (SRC, DEST, or
INs)
Ensure there is consistency when multiple route
reconfiguration or repair processes are invoked.
Ultimately converge where the most appropriate
route reconfiguration is performed.
Concurrent Node Movements
59
60. Challenges in Ad Hoc Networks
Limited wireless transmission range
Broadcast nature of the wireless medium
Packet losses due to transmission errors
Mobility-induced route changes
Mobility-induced packet losses
Battery constraints
Potentially frequent network partitions
Ease of snooping on wireless transmissions (security hazard)
60
61. Issues in Ad Hoc Networks
1. SpectrumAllocation and Purchase
2. Medium access scheme
3. Routing
4. Multicasting
5. Transport layer protocol Performance
6. Pricing shceme
7. QoS provisioning
8. Security
9. Energy management
10. Addressing and service discovery
11. Scalability
12. Deployment considerations61
62. 1. Spectrum Allocation and Purchase
FCC control the regulations regarding the use of radio
spectrum.
Who regulates the use of radio spectrum in INDIA??
To prevent interference, ad hoc networks operate over
some form of allowed or specified spectrum range.
Most microwave ovens operate in the 2.4GHz band, which
can therefore interfere with wireless LAN systems.
Frequency spectrum is not only tightly controlled and
allocated, but it also needs to be purchased.
With ad hoc networks capable of forming and deforming on-
the-fly, it is not clear who should pay for this spectrum.
62
63. 63
2.Medium Access Scheme
Distributed operation
Synchronization
Hidden terminal problem
Exposed terminal problem
Throughput
Access delay
Fairness: especially for relaying nodes
Real-time traffic support
Resource reservation
Ability to measure resource availability
Capability for power control
Adaptive rate control
Use of directional antennas
64. Media Access
TDMA and FDMA schemes are not suitable.
Many MAC (Media Access Control) protocols do not deal with host
mobility.
The scheduling of frames for timely transmission to support QoS is difficult.
In ad hoc wireless networks, since the same media are shared by multiple
mobile ad hoc nodes, access to the common channel must be made in a
distributed fashion, through the presence of a MAC protocol.
There are no static nodes, nodes cannot rely on a centralized coordinator.
The MAC protocol must contend for access to the channel while at the same
time avoiding possible collisions with neighboring nodes.
The presence of mobility, hidden terminals, and exposed nodes
problems must be accounted for when it comes to designing MAC
protocols for ad hoc wireless networks.
64
65. 65
Difference Between Wired and
Wireless
If both A and C sense the channel to be idle at the same time, they send
at the same time.
Collision can be detected at sender in Ethernet.
Half-duplex radios in wireless cannot detect collision at
sender.
A B C
A
B
C
Ethernet LAN Wireless LAN
66. IEEE has defined the specifications for a wireless LAN, called IEEE
802.11, which covers the physical and data link layers.
In IEEE 802.11, carrier sensing is performed
at the air interface (physical carrier sensing), and
at the MAC layer (virtual carrier sensing)
Physical carrier sensing
detects presence of other users by analyzing all detected packets
Detects activity in the channel via relative signal strength from other
sources
Virtual carrier sensing is done by sending MPDU duration information in
the header of RTS/CTS and data frames
Channel is busy if either mechanisms indicate it to be
Duration field indicates the amount of time (in microseconds) required to
complete frame transmission
Stations in the BSS use the information in the duration field to adjust their
network allocation vector (NAV)
802.11 - Carrier Sensing
66
67. A and C cannot hear each other.
A sends to B, C cannot receiveA.
C wants to send to B, C senses a “free” medium.
Collision occurs at B.
A cannot receive the collision.
A is “hidden” for C.
Hidden Terminal Problem
BA C
67
68. Exposed Terminal Problem
A starts sending to B.
C senses carrier, finds medium in
use and has to wait for A->B to
end.
D is outside the range of A,
therefore waiting is not necessary.
A and C are “exposed” terminals
A B
C
D
68
69. 69
3. Routing
Challenges
Mobility
results in path breaks, packet collisions, transient loops, stale routing
information, and difficulty in resource reservation
BW constraints
Error-prone and shred channel
Bit error rate BER: 10-5
~ 10-3
wireless vs. 10-12
~ 10-9
wired
Location-dependent contention
Distribute load uniformly
70. Routing
The presence of mobility implies that links make and break often and in an
indeterministic fashion.
Classical distributed Bellman-Ford routing algorithm is used to
maintain and update routing information in a packet radio network.
Yet distance-vector-based routing not designed for wireless networks,
still applicable to packet radio networks since the rate of mobility is not
high.
Mobile devices are now small, portable, and highly integrated.
Ad hoc mobile networks are different from packet radio networks since
nodes can move more freely, resulting in a dynamically changing topology.
Existing distance-vector and link-state-based routing protocols
are unable to catch up with such frequent link changes in ad hoc wireless
networks, resulting in poor route convergence and very low
communication throughput. Hence, new routing protocols are needed70
71. Routing protocols
Routing protocols
Purpose is to dynamically communicate information about all
network paths used to reach a destination and to select the from
those paths, the best path to reach a destination network.
Types of routing protocol
Distance –vector Routing Protocol
Distance vector protocols use a distance calculation (distance metric) plus
an outgoing network interface (a vector) to choose the best path to a
destination network.
The network protocol (IPX, SPX, IP,Appletalk, DECnet etc.) will forward
data using the best paths selected
Well Supported Protocols such as RIP have been around a long time and
most, if not all devices that perform routing will understand RIP.
71
72. Link state based
Selects the best routing path by calculating the state of each link
in a path and finding the path that has the lowest total metric to
reach the destination.
Link State protocols track the status and connection type of
each link and produces a calculated metric based on these and
other factors, including some set by the network administrator.
Link state protocols know whether a link is up or down and
how fast it is and calculates a cost to 'get there'.
Link State protocols will take a path which has more hops, but
that uses a faster medium over a path using a slower medium
with fewer hops.
72
73. Difference
If all routers were running a DistanceVector protocol, the path or
'route' chosen would be from A B directly over the ISDN serial link,
even though that link is about 10 times slower than the indirect route
from A C D B.
A Link State protocol would choose the A C D B path because it's
using a faster medium (100 Mb ethernet).
In this example, it would be better to run a Link State routing protocol,
but if all the links in the network are the same speed, then a Distance
Vector protocol is better.
73
74. 74
Routing (2)
Requirements
Minimum route acquisition delay
Quick route reconfiguration
Loop-free routing
Distributed routing approach
Minimum control overhead
Scalability
QoS provisioning
Support for time-sensitive traffic
Security and privacy
75. 4. Multicasting
Multiparty communcations are enabled through the
presence of multicast routing protocols.
The multicast backbone (MBone) comprises an
interconnection of multicast routers that are capable of
tunnelling multicast packets through non-multicast routers.
Some multicast protocols use a broadcast-and-prune
approach to build a multicast tree rooted at the
source.Others use core nodes where the multicast tree
originates.
All such methods rely on the fact that routers are
static, and once the multicast tree is formed, tree nodes will
not move. However, this is not the case in ad hoc wireless
networks.
75
76. 76
Multicasting
Robusteness
recover and reconfigure quickly from potential mobility-
induced link breaks
Efficiency
Min control overhead
QoS support
Efficient group management
Scalability
security
77. 5. Energy Efficiency
Mobile devices today are mostly operated by batteries. Battery
technology is still lagging behind microprocessor technology.
The lifetime of an Li-ion battery today is only 2-3 hours. Such a
limitation in the operating hours of a device implies the need for
power conservation.
For ad hoc mobile networks, mobile devices must perform both the
role of an end system (where the user interacts and where user
applications are executed) and that of an intermediate system
(packet forwarding).
Hence, forwarding packets on the behalf of others will consume
power, and this can be quite significant for nodes in an ad hoc
wireless network.
77
78. 78
Energy Management
Tx power mgmt
MAC: sleep mode
Routing: consider battery life time: load balancing
Transport: reduce ReTx
App
Battery energy mgmt
Extend battery life by taking adv of chemical properties,
discharge patterns, and by the selection of a battery from a set
of batteries
Processor power mgmt
Device power mgmt
79. 6. TCP Performance
TCP is an end-to-end protocol designed to provide flow and
congestion control in a network. TCP is a connection-
oriented protocol; hence, there is a connection
establishment phase prior to data transmission.The
connection is removed when data transmission is completed.
TCP (Transmission Control Protocol) assumes that nodes in
the route are static, and only performs flow and
congestion activities at the SRC and DEST nodes.
79
80. TCP relies on measuring the round-trip time (RTT) and packet loss
to conclude if congestion has occurred in the network.
In telecommunications, the round-trip delay time
(RTD) or round-trip time (RTT) is the length of time it takes for
a signal to be sent plus the length of time it takes for an
acknowledgment of that signal to be received.This time delay
therefore consists of the transmission times between the two points of
a signal.
TCP is unable to distinguish the presence of mobility and
network congestion.
Mobility by nodes in a connection can result in packet loss and long
RTT.
Enhancements needed to ensure that the transport protocol performs
properly without affecting the end-to-end communication throughput.80
81. 7. Service Location, Provision, and
Access
Ad hoc networks comprise heterogeneous devices and
machines and not every one is capable of being a server.
The concept of a client initiating task requests to a server for
execution and awaiting results to be returned may not be
attractive due to limitations in bandwidth and power.
Concept of remote programming as used in mobile agents is
more applicable since this can reduce the interactions
exchanged between the client and server over the wireless
media.
Also, how can a mobile device access a remote service in an
ad hoc network? How can a device that is well-equipped
advertise its desire to provide services to the rest of the
members in the network?All these issues demand research.
81
82. 8. Security & Privacy
Ad hoc networks are intranets and remain as intranets unless
connected to Internet.
Such confined communications have already isolated
attackers who are not local in the area.
Through neighbor identity authenication, a user can know if
neighboring users are friendly or hostile.
Information sent in an ad hoc route can be protected in some
way but since multiple nodes are involved, the relaying of
packets has to be authenicated by recognizing the originator
of the paket and the flow ID or label.
82
83. 83
Security
DoS attack
Resource consumption
Energy depletion
Buffer overflow
Host impersonation
Information disclosure
Interference
84. 84
9. Deployment Consideration (1)
Adv. in ad hoc net
Low cont of deployment
Incremental deplyment
Short deplyment time
Reconfigurablity
Scenario of deployment
Military deployment: data-centric or user-centric
Emergency operation deployment: hend-held, voice/data,
< 100 nodes
Commercial wide-area deployment: e.g.WMN
Home network deplyment
85. 85
Deployment Consideration (2)
Required longevity of network
Area of coverage
Service availability: redundancy
Operational integration with other infrastructure
Satellite network, UAV(unmanned aerial vehicles), GPS
Cellular network
Choice of protocols
TDMA or CSMA-based MAC?
Geographical routing (using GPS)
Power-saving routing ?
TCP extension ?